Generally, in case of such tubular objects through which the water passes, such as a water service pipe, feed and drain pipes of a water tank, and so forth, while the tubular objects are used for a long time, active oxygen in water reacts with ferreous components of the tubular objects, so that the interior of the tubular objects is not only corroded to generate rust, but is deposited with such rust, foreign matters and so on. In other words, the interior of the tubular objects generates scales, slimes, slurries and so forth, and thus the tubular objects have a shortened service life span and interrupt the flow of the water. Further, the water passing through these tubular objects contains various kinds of matters harmful to a human body, such as iron oxides, impurities, germs, etc., so that such water is not sanitary.
In order to eliminate this insanitary factor of the tubular objects, a cleansing tool, for example a brush, is introduced into the interior of the tubular objects to remove rust, scales and so on. Alternatively, the tubular objects having the interior corroded may be exchanged with new ones. In this manner, the insanitary factor of the interior of the tubular objects is removed. However, this method allows the insanitary factor to be removed, but has an inefficiency problem in that in the course of cleansing or exchanging the tubular objects, relatively much time, labor power, equipment are required along with high cost.
Further, a method for treating water using a pipe cleanser or a high frequency generator has been used to extend a life span and an insanitary factor of the tubular objects. However, the method using the pipe cleanser incurs another problem according to use of chemicals. Further, an apparatus requiring power, such as the high frequency generator, requires consumption of energy and complicated equipment.
For this reason, recently, in industrial sites, there has been used a water treatment apparatus, which is non-powered, environmentally-friendly and simply equipped/installed, having an electrostatic generator to generate static electricity so as to ionize water with an electrostatic field, thereby purifying water using the ionization and simultaneously cleansing the inside of the tubular objects.
A water treatment apparatus having an electrostatic generator which is mounted to the tubular objects and purifies water and cleanses the inside of the tubular objects using ions as above is disclosed in Korean Patent No. 0312152. In terms of this water treatment apparatus, referring to FIG. 1, the water treatment apparatus includes an electrostatic generator 10 that generates an electrostatic field by contact friction with water by allowing the water to flow through, a thermal insulator pipe 20 into which the electrostatic generator 10 is inserted and isolates internal and external heat transmission to prevent deterioration in performance of the electrostatic generator 10 according to generation of moisture, closures 30 that prevents water from being introduced into the thermal insulator pipe 20, a housing 400 into which the thermal insulator pipe 20 and the closures 30 are inserted, housing connectors 450 coupled to both sides of the housing 40 and simultaneously to a tubular object. The water treatment apparatus having this electrostatic generator 10 further comprises a metal casing 50 as shown in FIG. 2, for protecting the housing 40 molded out of copper and other components inserted into the housing 40, and completely isolating heat transmission from the outside.
The electrostatic generator 10 is fixed to pipes 15 and 15′ by forming carbon, copper, etc. either into a rod 12 or tube 12′ or into a cylindrical structure provided with a plurality of inside holes in order to increase a contact area with water. Thus, water molecules flowing through the tubular objects are ionized by an electrostatic field generated by friction with the electrostatic generator 10. Activated water containing the ions prevents and removes generation of scales and so on in the inside of the tubular objects, and inhibits proliferation of germs, bacteria, etc. included in water. Thus, the water treatment apparatus having the electrostatic generator 10 is non-powered, eco-friendly and simply equipped/installed, thus being of use.
In this manner, the water treatment apparatus finally mounts the housing 40, into which the electrostatic generator 10 is inserted, to the metal casing 50, then directly connecting to the tubular objects.
The metal casing 50, as shown in FIG. 2, includes a cylindrical metal casing body 52 in which the housing 40 and the housing connectors 45 are mounted, and discal metal sealing caps 54 coupled to both sides of the cylindrical metal casing body 52. Here, the center portion of each of the metal sealing caps 54 is provided with a fastening bore 54a, which is adapted to allow one side of each of the housing connectors 45 to be exposed and connected to the tubular objects.
Conventionally, a thermal insulator such as a synthetic resin foam is inserted and filled between the metal casing 50 and the housing 40 to completely isolate heat transmission from the outside, so that the sealing caps 54 of the metal casing 50 prevents the escape of the thermal insulator. Thereby, a sealing structure is obtained.
As set forth above, the prior art inserts and fills the thermal insulator between the metal casing 50 and the housing 40 to isolate heat transmission from the outside. However, it is difficult to compactly fill the thermal insulator so as not to leave any empty space between the metal casing 50 and the housing 40. For this reason, it is impossible to completely isolate heat transmission from the outside by filling the thermal insulator. Thus, even if the thermal insulator is filled, condensed water is inevitably generated in the space between the metal casing 50 and the housing 40 by a temperature difference between the inside and the outside. Further, in the case where the apparatus needs to exchange its components or that to be repaired due to generation of its internal defect, it is difficult to disassembly the apparatus because the thermal insulator is fixedly attached inside the apparatus. Thus, use of the thermal insulator leads to an increase in product costs. Particularly, because the outside of the apparatus has much higher temperature than the inside thereof in the summer, a decrease in pressure according to liquefaction of internal air (moisture), external air accompanied with the moisture continues to be introduced into the apparatus. In this manner, the moisture continuously introduced together with the air is liquefied, so that the condensed water is considerably generated in the summer. The condensed water generated in this manner is frozen in the winter, and thus there is a possibility to spoil the apparatus according to volume expansion. In particular, when the condensed water is accumulated in the apparatus for a long period, the condensed water causes the apparatus to be corroded and to be shortened in its life span. Further, the condensed water leaks from a coupling part of the casing body 52 and the sealing caps 54 or the fastening bore 54a of the sealing caps 54 to the outside, so that an external surface is corroded to generate rust. Eventually, as the condensed water is leaked from a coupling part of the casing body 52 and the sealing caps 54 or the fastening bore 54a of the sealing caps 54 to the outside, a user is compelled to misunderstand that any defect exists in the performance of the apparatus, which leads to a problem in that there is a decrease in reliability of the performance of the apparatus.